You want your mobile two way radio on your desktop, or you want to convert it into a base station for your shack. You've picked out radio, the antenna, and location for your rig. All you need is the power supply. There's just one minor detail. You know exactly how much power you need, but what type of power supply should you choose?
There are several types of power supplies. These include those that are unregulated, ripple regulated, regulated linear and switching. In this article we are going to focus on comparing the two types we carry at Buy Two Way Radios for use with our mobile and base station two way radios. These two types of power supplies are Linear (regulated) and Switching.
Linear Power Supplies
Linear power supplies have been around for a long time. At one point it was the only choice for power supplies. They produce clean, quiet DC voltage with little to no electromagnetic noise. This makes the linear power supply a great choice for use in radio communications. A linear power supply takes the AC line voltage and puts it through a transformer to lower the voltage, then a through a rectifier and filters to convert it to DC output voltage.
Linear power supplies are well suited for use with radios, but they do have a few drawbacks. The large transformers and filter circuits generate a lot more heat, which in turn requires large heat sinks to compensate. Due to all these components, they are also quite heavy. The more power they provide, the heavier and larger they become. In addition, their energy efficiency is fairly low compared to a switching power supply.
Switching Power Supplies
Switched Mode or Switching power supplies are smaller, lighter and more advanced. They also operate at considerably higher efficiency than a linear model. Switch power supplies also generate less heat, which can be an important advantage when operating in a small ham shack or in an area with limited air circulation.
The drawback to switching power supplies is that they can introduce RFI noise. This can be a problem with inexpensive, lower quality models and small, "brick" style power supplies intended for general consumer electronics, but is not generally an issue with power supplies intended for radios and built by high quality, name brand manufacturers. Even so, the noise can be sometimes be alleviated by using EMI chokes or ferrite cores on external wiring to the radio.
Before you shop around for power supplies, it is important to know that they are not all the same. It can make all the difference between choosing the right power supply for your radio, and not having all the power you really need.